15 February 2011
Two big news items to report. First, students had a great time experimenting with the laser projection system. The picture on the left below shows them in my classroom with a can of spray fog lighting up the beam as students learn how to use the software. The right image shows the four lasers (2 reds, green and blue) and the third image shows the recently completed laser show that we are showing this week on the wall in the corridor between classes.
Last Saturday we met with one of our professional assistants to complete the programming on a project we have been working on for over a year. This project uses LabView software to automatically move measurement equipment 0.01 millimeters at a time and take laser power readings. We developed a program that takes 2000 readings in about 5 minutes and logs them into a file for analysis. Students were thrilled to complete this programming effort. When we tried it out Saturday afternoon it worked perfectly. Our next step will be to set up the lasers and optics and use the new program to take real data. The block diagram of the program we developed in shown below.
27 January 2011
We have been working for many weeks setting and wiring our laser projection system and now it is just about ready to go. We have also been learning how to use the software. Within the next couple of weeks we should be able to roll out some new laser displays that people will be able to see in the hallway in the School of Rhetoric.
Below is a photo of the completed system. Most of it is power supplies and control circuits, but the four lasers (2 reds, one green and one blue) are arranged in the lower right corner. In the center foreground are the x-y scanners that deflect the beams so they can trace out images on a wall or screen.
The students have had a lot of fun with this. Along the way they have learned how to solder, use heat shrink, operature a wire stripper, install wireways and wire ties, and wire up electrical connections. All essential knowledge for work in a lab!
18 January 2011
It's been a while since an update! Here is a report on our day last November when we hosted 11 students from City School. They came to our lab and our LOS students presented a lesson on various wave and light phenomena such as reflection, refraction, diffraction and interference.
Here we are gathering in Mr. Mays' classroom for cookies and lemonade prior to the presentation. Sam Itskin was our first presenter, here shown illustrating different types of reflection with a laser pointer.
Then we moved into the optics lab. Douglas Steinman described reflection and refraction (sorry, no photo). Next up was David Leach illustrating diffraction, followed by Grace Womack with a description of wave interference. (Grace is developing her markerboard technique!)
Below Caleb Kyle is working on lining up part of the diffraction demonstration. As you see, the City School kids were fully engaged, even though our tiny lab was very crowded!
The two photos below were taken when we combined green and red lasers to produce a nice orange beam.
It was a great time and the students from City School thoroughly enjoyed it.
14 October 2010
After more painstaking weeks of re-aligning our laser with the new spatial filters we installed we may be ready to shoot another hologram tomorrow afternoon. Meanwhile, we have been assimilating several new freshmen into the Laser Optics Society, and they are now getting busy studying the resource packets and taking quizzes to begin moving up in the ranks. It's great to see these new faces.
On November 11 we will be hosting a group of middle school students from another school. I and the Regents LOS students have developed a presentation around the various behaviors of light which we will demonstrate in the optics lab with our visitors.
Below are a couple of images from our training day two weeks ago. On the left are three of our new freshmen, and on the right is yours truly talking about wave interference.
We are ready to begin a new year of work in the Laser Optics Lab. We were so busy last spring learning how to make holograms I didn’t have time to update this website much. We made a number of successful holograms, but each of them was deficient in some way. This led us to a repeated process of trials, improving the image in one way, while discovering another way to create some new problem! It was great and the students really got to see how life in labs works! This year we will continue making holograms for a few weeks, building on what we already know. Hopefully we will succeed in making some really good ones. The photo on the right shows our hologram setup.
We also will begin working on assembling a new laser projection system. With this equipment and the software for designing and controlling the laser images, we will be able to project images of graphics and text onto a wall. The photo on the left shows all the projector system parts. We have to figure out how to set up all of this equipment!
Finally, note that our lab has a new look with a nice flat black paint job! This not only makes the lab look cool, the primary purpose is to cut down on light reflected from walls that might degrade our experiments.
6 Jan 2010
We are very close now to taking our first holographic images. Beam alignment is essentially complete, our film plates are in route to us, and our higher powered laser for the holography has arrived! We hope to have our first holographic images in a couple of weeks.
Below are some images from the LOS meeting last night. First, a shot of the marker board in the lab. You can tell we are serious about this! In the next 3 pictures you see us last night trying to figure out how to assemble the positioning devices that we will use to support our laser. (That took us 2 hours.) The next 4 pictures show our set up. We are using the white cards to examine the quality of the light as it spreads out. As you see, the large green disks of light are very uniform, which is due to the equipment we are using and should give high quality images. Next is a shot of the cards in the dark. You can see a bit of stray reflected beam on the wall to the left which we will need to eliminate when we use our higher powered laser. Finally,a shot of one of our Grade 2 members at the optical table.
2 December 2009
I am pleased to announce that we now have our first two Grade 2 Members in the Laser Optics Society, senior Evan Jones and freshman Grace Womack. To achieve this Grade students must achieve a minimum score of 84 on four separate quizzes covering optics, lasers, mechanical equipment, and vocabulary. Additionally, they must have logged a minimum of 15 hours in the lab. This is a great milestone for the Laser Optics Society. At present there are two or three other students who are actively preparing for the quizzes required for Grade 2.
For the past month in the lab we have been setting up and aligning the equipment to produce holograms. We are very close to being finished with this painstaking process, and with the film and a new laser arriving just after Christmas we hope to be making holograms by mid-January!
23 October 2009
This week we installed a new shelving system so that our electronics and power supplies would not have to sit on the optics table where the optical components are. The LOL is looking cleaner and more professional every week! The first photo below shows student LOS members after the new equipment was installed. Yesterday we hosted our first open house for the LOL. On display was our project to transmit and receive music with a laser beam. Student LOS members met with visiting students (and one or two parents) to explain the operation of the system.
14 October 2009
The LOS is now up to 8 Grade 0 members and 3 Grade 1 members. Thirteen were here last night to work on learning how to use a beam splitter, transmission grating and perform simple beam alignment. More and more students are working on preparations for the quizzes so they can advance in the membership ranks! The photo below is from our work last night. Beams from red and green lasers (the black cylinders on either side) are combined at the beam splitter in the center and separated again by the grating just upward and to the right of center. The split beam is hitting the white paper behind the grating. The reason the center spots are orange is because that's what color you get when you mix red and green light! Another thing you can in the image is that we need some training on how to take good photos in the dark!
7 October 2009
Two big milestones to report. We now have our first three Grade 1 members! To achieve Grade 1 students must pass quizzes on two reading packets, so these students are really serious about the work in the LOL. Evan Jones, David Leach, and Douglas Steinman are now at Grade 1.
Last night we spent considerable time aligning the polarization on our laser beam modulator. This alignment, which was quite tricky, considerably improved the sound quality of the music signal we are able to transmit with the laser beam, and the dozen or so students who were here felt the satisfaction of reaching this project goal. Now we will begin experimenting with beam splitters and diffraction gratings so we can gain experience with these types of optics.
29 September 2009
With some 10 students here at the Laser Optics Lab for 3 hours Friday afternoon, we achieved our first major success: We transmitted a music program through a laser beam. We when heard music coming out of our speaker, which was connected to a photodetector, there was a mighty cheer and the students went nuts with joy! It was a lot of fun. The transmitted signal wasn't perfect, so we still have work to do and will tackle it again tonight.
We now have 8 members in the Laser Optics Society who achieved Grade 0 status, meaning they have completed all safety training. Many more are in progress. The photo below is of our first 8 Grade 0 members. In the foreground is the setup for our music transmission project.
18 September 2009 5:00 pm
We are now working in the lab on our first project, which is to modulate a laser with a music program, detect and demodulate the beam, and feed the signal to a powered loudspeaker. When we get it to work we will be transmitting the audio program through the air with the laser. As of the end of our lab time today, we haven't gotten the modulator and detector to work yet. More research is required.
We now have nearly 20 students who have completed or almost completed their safety training. The photos below are from the 15 September meeting when we began setting this project up. If the lab looks messy - it is! Today we got most of our new equipment unpacked and put away, so the place looks much neater. That piece of cardboard you see in the pictures is our beam blocker. This is part of laser safety 101 - don't let the beam leave the table where it might hit the shiny red tookbox in the background and reflect off and hit someone in the eye. Always terminate the beam!
Also as of today, there are many more students not pictured in these photos from Tuesday.
This month we passed our first milestone, which was to acquire and set up the optics table. This was no easy task, since the optics table weighs over 600 pounds! The first photo shows the table being lifted into position with a small crane. In the second photo the optics table is in position. The third photo is a close up of the inner tubes supported the table. This provides an air cushion for the table to help with vibration isolation. Now that the table is set up we are ready to begin purchasing optical components for the projects we will begin working on in the fall.